Volcanoes and Earthquakes: Formation and Types
Volcanoes
A volcano is a geological structure from which magma (molten rock) and gases from inside a planet rise and emerge. This generally occurs in violent episodes called eruptions. A volcano is the only conduit that puts the terrestrial surface in direct communication with deep levels of the Earth’s crust. In the mantle’s depth, magma under pressure rises, creating magma chambers below or within the cracks in the rocks of the crust. The Earth’s crust provides an outlet for the intense pressure,
Read MoreIndustrial Rocks and Minerals: Types and Uses
Industrial Rocks
Rocks that are exploited by their physicochemical properties, regardless of the substances and energy that may be extracted.
- Aggregates: Formed by stones or pieces of various sizes. Used mainly in public works or construction (e.g., basalt, quarries, marble, slate, sand, gravel).
- Agglomerates: Formed by a compact mass of material, with a cohesive agglomerating material (e.g., marble, cement, lime, gypsum, margin, clay).
- Construction Rocks: Divided into ornamental rocks, which can be
Geological Regions: Siliceous, Limestone, and Shale
Siliceous terrain comprises ancient rocks from the Precambrian and Primary eras. It is mostly in the western peninsula (Galicia, León, Extremadura) and has ramifications to the western part of the Cantabrian mountain range, the CS, Montes de Toledo, and Sierra Morena. It is also located in isolated areas such as the axial zone and some sectors of the Pyrenees, Iberian system, coastal mountain range, and the Catalan-Penibético system. The prevailing rock is granite, and the landscape is determined
Read MoreTypes of Sedimentary Deposits and Soil Genesis
Types of Sedimentary Deposits
Lacustrine deposits: These occur when earth is moved or transported by rivers and streams and deposited on lake bottoms.
Proluvial deposits: These are materials occupying the bed of dry streams.
Fluvial deposits: These are formed by sediments that accumulate from the activity of rivers and the processes associated with gravity sliding.
Wind deposits: These are formed through the accumulation of transported material, forming dunes and sand dune materials.
EOI: A special material
Read MoreGeological Eras and Landforms of the Iberian Peninsula
Geological Eras of the Iberian Peninsula
Paleozoic Era: Began 570 million years ago and lasted until 230 million years ago. During this era, two plates, or continents, were separated by the Sea of Tethys. Two orogenies occurred: the older Caledonian, which barely affected peninsular space, and the Hercynian, which developed during the Carboniferous period. As a consequence, a great mountain range arose in a NW-SE direction, becoming a massif called the Hesperian Massif, which occupies much of central
Read MoreIbn Tulun Mosque: A Masterpiece of Islamic Architecture in Cairo
The Grand Mosque of Ibn Tulun
From his palace, al-Katai, Ibn Tulun governed with authority. His time in Samarra, where he grew up, is remembered for its giant brick mosques, built in the Iraqi tradition. He decided to build a similar prayer structure in Fostat (near the future city of Cairo), of monumental proportions. Unlike the Nile Valley, where stone was widely used since the Pharaohs for temples and tombs, Ibn Tulun used brick and stucco cladding, a technique common in Mesopotamia. The construction
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